Three people were killed and at least six others were wounded Tuesday night at the District's southern tip in an outbreak of gunfire that may have left the city's largest number of victims in 15 years.

A 10th person was found shot several blocks away, but police said they were unsure whether he was a victim of the same flurry of gunfire, which one witness likened to a war zone.

Of the three who were killed, two died at Washington Hospital Center, a spokeswoman there said. Three other victims were listed in critical or serious condition. Shooting victims included six men and three women, possibly including a 16-year-old, authorities said. The other victims appeared to be in their 20s and 30s, fire officials said.

Three people were in custody late Tuesday night, but no charges had been filed, said D.C. Police Chief Cathy L. Lanier. Four police officers were injured while pursuing them.

The shooting occurred about 7:30 p.m. in the 4000 block of South Capitol Street as people stood outdoors and a gunman began "spraying [bullets] into a crowd," Lanier said.

Two people said the victims were clustered in front of a brick apartment building on South Capitol Street. Accounts provided by witnesses and neighbors indicated that the shooting may have been a drive-by.

Police sources said an AK-47 assault rifle may have been used. A man who said he was in the area at the time recounted the sounds he heard as "pat, pat, pat, pat, pat," followed by a loud boom.

Then, "all I saw was bodies dropping," he said. "It was like Vietnam."

Another witness said that as bodies fell, "it was like a pileup at a football game."

About the same time, a shooting victim was found a blocks away. Authorities said it was possible that he had been hit in the South Capitol Street outbreak.

The motive for the gunfire could not be learned immediately and was part of an intensive police investigation.